SIGSHR, I don't think it is black powder. From what I've read, I am thinking my H&R might be a "3rd Model AUTOMATIC EJECTING 3rd Variation (1913-1915), which was made to handle smokeless/Nitro powder loads." But I'm not an expert for sure. Just grabbing info from other sites and trying to make an educated guess. I just hope I have enough education to do that.